Cisco still can’t write decent applications for its own IOS-XR operating system.
Note that IOS-XR is a core component of all Cisco software strategies for the next decade. This is not a legacy operating system like IOS, IOS-SX etc
On the 22nd of February 2016 I have raised a case with Cisco notifying them that you are simply unable to retrieve any route learnt via BGP, using the XML agent. As of today, 14th of April 2017, thus almost 14 months later, this case is still unsolved. Discalimer: the following have been tested on ASR9K routers running IOS-XR 5.1.3, 5.3.3, 6.0.2 and 6.1.2 32-bit having really big amounts of routes learned through BGP, a pretty good chunk of the whole Internet table.
Cisco IOS-XR: the buggy XML API : https://mirceaulinic.net/2017-04-14-cisco-xr-xml-agent-fun/